RFR: 8367795: HeadlessMalfunctionTest may fail due to timeout

[Sergey Bylokhov]

The default timeout factor for tests was changed by [JDK-8260555](https://bugs.openjdk.org/browse/JDK-8260555). Since then, the HeadlessMalfunctionTest may occasionally fail on some systems when run in parallel with other tests. When executed alone, it usually completes in 30–40 seconds, but under CPU spikes it can take up to ~120 seconds, which can occasionally cause it to fail.

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Commit messages:
 - 8367795: HeadlessMalfunctionTest may fail due to timeout

Changes: https://git.openjdk.org/jdk/pull/27397/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27397&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367795
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27397.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27397/head:pull/27397

PR: https://git.openjdk.org/jdk/pull/27397